The solution to the Ship of Theseus is that telos, not atomic physics, is how the vernacular We identify and organize the contents of our existence. I am the same me as the me of 10 years ago, even though we have zero cells in common, because we are iterations of an ongoing physical phenomena the same root cause: my conception.
Its a common myth that our cells all die and are replaced by new ones, but that is not actually true, it is true for the vast majority of cells tho.
One of the most extreme example where this is not true, are the female gametes aka the egg cells. They are all created before birth and are never replaced. Quite the opposite of the male counterpart where the production of gametes starts 10+ year after birth and usually continues for the rest of the life.
And so it is with Theseus and his Ship.